Vue.component("top-header",{
    template:`<nav class="navbar navbar-default navbar-fixed-top navbar-inverse">
   <div class="container-fluid">
     <div class="navbar-header">
        <router-link to="/" class="navbar-brand">首页</router-link>
        <router-link to="/notice/" class="navbar-brand">公告管理</router-link>
        <router-link to="/" class="navbar-brand">帮助</router-link>
     </div>
  </div>
</nav>`
})